1. Field of the Invention
The present invention relates to a substrate processing device, a substrate conveying device, and a substrate processing method, and in particular to a CVD device, dry etching device, ashing device, sputtering device, or other dry process device for manufacturing LCDs or semiconductors.
2. Description of the Related Art
FIGS. 27 and 28 depict configurational examples of a conventional single-piece substrate processing device.
FIG. 27 is a diagram illustrating an in-line LCD plasma CVD device. A first conveyance stand Ti is connected to a load-side cassette stand S1, a load-side substrate preparation chamber L1 is connected by means of a gate valve to the first conveyance stand T1, and a first conveyance chamber T2 is connected by means of a gate valve to the load-side substrate preparation chamber L1. A preheating chamber H is connected by means of a gate valve to the first conveyance chamber T2. In addition, a first film-forming chamber R1, a second conveyance chamber T3, a second film-forcing chamber R2, a third conveyance chamber T4, and a third film-forming chamber R3 are sequentially connected by means of gate valves to the first conveyance chamber T2; an unload-side substrate preparation chamber L2 doubling as a substrate-cooling chamber is connected by means of a gate valve to the third conveyance chamber T4; a second conveyance stand T5 is connected by means of a gate valve to the unload-side substrate preparation chamber L2; and an unload-side cassette stand S2 is connected to the second to conveyance stand T5.
The cassette stands S1 and S2 can accept and discharge substrate cassettes that carry substrates and convey each individual substrate to the load-side substrate preparation chamber L1 by operating in tandem with the conveying device of the first conveyance stand T1, whereat the conveying device of the first conveyance chamber T2 conveys the substrates of the load-side substrate preparation chamber L1 to the preheating chamber H, and the substrates of preheating chamber H to the first film-forming chamber R1. The conveying device of the second conveyance chamber T3 conveys substrates from the first film-forming chamber R1 to the second film-forming chamber R2; the conveying device of the third conveyance chamber T4 conveys substrates from the second film-forming chamber R2 to the third film-forming chamber R3 or from the third film-forming chamber R3 to the unload-side substrate preparation chamber L2; and the conveying device of the second conveyance stand T5 conveys substrates from the unload-side substrate preparation chamber L2 to the unload-side cassette stand S2. The conveying devices of the first conveyance stand T1, first conveyance chamber T2, second conveyance chamber T3, third conveyance chamber T4, and second conveyance stand T5 are each capable of conveying substrates independently. Further, the conveyances of the substrate by the conveying devices of the first and second conveyance stands T1 and T5 are carried out in the atmosphere. On the other hand, the conveyances of the substrate by the conveying devices of the first, second and third conveyance chambers T2,T3 and T4 are carried out in a vacuum.
FIG. 28 is a diagram illustrating a cluster-type LCD plasma CVD device. Vacuum chambers are arranged in a circle along the side walls of a vacuum conveyance chamber T2 shaped as a heptagon on the outside. The following devices, listed in the clockwise direction when viewed from the front, are sequentially connected in an airtight manner by means of gate valves: a substrate heating chamber H, a second processing chamber R2 serving as a film-forming chamber, a fourth processing chamber R4, a second substrate preparation chamber L2 provided with a load lock chamber, a first substrate preparation chamber L1, a third processing chamber R3 serving as a film-forming chamber, and a first processing chamber R1.
The vacuum conveyance robot A of the central vacuum conveyance chamber T2 is equipped with a conveyance arm and is capable of conveying substrates to and from any of the aforementioned plurality of chambers H, R1-R4, and L1-L2 in the vacuum. A first cassette stand S1 and second cassette stand S2 for loading or unloading substrate cassettes are disposed opposite the first substrate preparation chamber L1 and second substrate preparation chamber L2, respectively. Atmospheric conveyance robots B1 and B2, each having a set of conveyance arms, are provided to an atmospheric conveyance stand T1 between the first substrate preparation chamber L1 and first cassette stand S1, and the second substrate preparation chamber L2 and second cassette stand S2, respectively. The atmospheric conveyance robots B1 and B2 are designed to convey substrates between the first and second cassette stands S1 and S2, and the first and second substrate preparation chambers L1 and L2 in the atmosphere.
A substrate is transported to the substrate heating chamber H after being received from the first substrate preparation chamber L1 by the conveyance arm of the vacuum conveyance robot A inside the vacuum conveyance chamber T2. The heated substrate is taken out by the vacuum conveyance robot A from the substrate heating chamber H, transported to any of the first to fourth processing chambers R1 to R4, and processed there.
After substrate processing has been completed, the substrate is received by the conveyance arm of the vacuum conveyance robot A and mounted in the second substrate preparation chamber L2. The second substrate preparation chamber L2 stores processed substrates until all the substrates have been processed in the first substrate preparation chamber L1. The substrates are cooled while in storage.
When the processing of all the substrates has been completed, the substrate cassette is taken out by the second atmospheric conveyance robot B2 from the second substrate preparation chamber L2 and is moved to the second cassette stand S2. The substrate cassette loaded with unprocessed substrates and mounted on the first cassette stand S1 is transported by the first atmospheric conveyance robot B1 to the first substrate preparation chamber L1, and the above-described processing is continued.
Although a cluster-type substrate processing device was described above with reference to an LCD plasma CVD device, the same reasoning applies to an LCD dry etching, ashing, or LCD sputtering device. The processing chambers R1 to R4 are used as film-forming, etching, and sputtering chambers, and the substrate heating chamber H may be dispensed with when there is no need for a step in which the substrates are heated prior to film forming or sputtering.
In the conventional in-line-type plasma CVD device shown in FIG. 27, robots used exclusively for loading and unloading are arranged symmetrically about the corresponding processing chambers, reducing the dead time for the reaction chambers R, substrate preparation chambers T, and substrate heating chamber H, and resulting in increased throughput. This system is disadvantageous, however, in that it uses a large number of robots, and is therefore costly and has a larger footprint.
The conventional cluster-type plasma CVD device depicted in FIG. 28 is also effective as a device that requires a plurality of reaction chambers R and delivers high throughput. When, however, an attempt is made to equip a single CVD device with more reaction chambers in order to achieve higher throughput, the following measures must be taken to increase throughput with the same chamber structure: (1) the substrate heating chamber H must be provided with a plurality of charges (slots), (2) a frog-leg, double-hand robot A is needed to reduce the dead time of processing chambers R, (3) high-speed conveyance robots capable of 360xc2x0 rotation must be devised, and other measures aimed at increasing the processing capacity of common components must be taken.
A resulting drawback is that the vacuum conveyance chamber T2 and substrate heating chamber H become more expensive, and the vacuum chambers increase in size. The technical issues encountered during attempts to achieve such increases in processing capacity by adopting a linear approach are particularly daunting in the case of LCD production lines, for which the increase in substrate dimensions is considerable. Enormous costs are thus involved. Even when the substrate dimensions remain the same as in the past and the number of reaction chambers is limited to one or two in order to provide a device whose throughput remains low but adequate, the drawback is that, in contrast to the case described above, the share of common components increases in terms of cost and footprint, resulting in considerable losses.
The above-described problems are common to dry etching/ashing composite devices and sputtering devices, and semiconductor manufacturing devices are affected in the same manner.
To obtain a device that is flexible enough to be adapted to a variety of desired throughputs, a single device must be composed of added-value film-forming chambers, and a sufficient number of such devices must be provided to achieve the desired throughput. To enhance the overall performance of these devices and to render them more efficient, it is necessary to design a system that is less expensive, is more compact, and can realize a throughput that is as good as or better than the throughput per conventional cluster-type film-forming chamber.
It is also necessary to minimize the size and number of the device chambers and to arrange the chambers in a square configuration in order to overcome another drawback of prior art; namely, to eliminate unneeded footprint and to provide an efficient device. Yet another requirement is that in order to trim costs and to provide an efficient device, it is necessary to take the same measures as those described above: that is, to reduce the number of chambers constituting the device and to minimize the size of these chambers. It is also necessary to simplify the conveyance system (to reduce the number of drive shafts) and to simplify the interior structure of the chambers.
In view of this, a CVD device having a uniaxial (in-line) configuration such as that shown in FIG. 29 has been proposed. First, some of the conventional vacuum chambers (a total of two to three chambers, of which one is a substrate heating chamber, and the rest are substrate preparation chambers) are integrated into a single chamber by combining the functions of the substrate preparation chambers and substrate heating chambers (functions that have been performed by separate chambers in the past) in order to reduce the number of chambers, and providing a new substrate preparation chamber L/H equipped with a substrate heating mechanism. The vacuum chambers can thus be composed of three chambersi a substrate preparation chamber L/H, a vacuum conveyance chamber T2, and a first film-forming chamber R; and the CVD device can be arranged in a square configuration, and the unneeded footprint eliminated, by adopting an axial chamber arrangement, with the vacuum conveyance chamber T2 disposed in the middle. Here, T1 denotes an atmospheric conveyance chamber T1.
It is impossible, however, for the device depicted in FIG. 29 to operate such that substrates are sequentially conveyed in the manner provided by a conventional cluster system or that parallel processing is performed by continuously starting sequential processing routines. Each of the processing cycles (including the conveying time) is therefore added in series to the intervals between the processing cycles of the device. Assuming, for example, that the device has a substrate preparation chamber for single-piece processing and a single-hand substrate conveyance mechanism, the interval between the processing cycles (substrate discharge interval) of the device will be as follows.
Substrate loading time+Preparation chamber evacuation and heating time+Conveyance time (from substrate preparation chamber to film-forming chamber)+Reaction chamber processing time+Conveyance time (from film-forming chamber to substrate preparation chamber)+Preparation chamber atmospheric venting time+Substrate unloading time
It is thus impossible for this system to achieve the same throughput per film-forming chamber as that of a conventional cluster system.
An object of the present invention is to overcome the above-described drawbacks of prior art and to provide a substrate processing device, substrate conveying device, and substrate processing method in which the substrate processing device has a uniaxial configuration, the substrate conveyance time can be reduced to produce a shorter substrate processing cycle, and the number of substrates processed per unit of time can be increased.
The substrate processing device of claim 1 is a substrate processing device comprising a substrate processing chamber for subjecting substrates to prescribed processing; a substrate mounting unit for mounting substrates in the substrate processing chamber; a substrate storage unit for storing unprocessed substrates scheduled to undergo prescribed processing in the substrate processing chamber, or processed substrates that have undergone the prescribed processing therein; and a substrate conveying device for conveying the unprocessed substrates from the substrate storage unit to the substrate mounting unit inside the substrate processing chamber, and conveying the processed substrates from the substrate mounting unit inside the substrate processing chamber to the substrate storage unit; this substrate conveying device being provided with two simultaneously operating substrate conveying units such that one of these substrate conveying units is used to convey the unprocessed substrates from the substrate storage unit to the substrate mounting unit inside the substrate processing chamber; and the other substrate conveying unit is used to convey the processed substrates from the substrate mounting unit inside the substrate processing chamber to the substrate storage unit. The substrate processing chamber, substrate storage unit, and substrate conveying device are disposed along a single axis.
In the substrate processing device of claim 1, the substrate conveyance time can be reduced by about half by providing the substrate conveying device with two substrate conveying units and simultaneously performing an operation in which substrates are conveyed from the substrate storage unit to the substrate mounting unit in the substrate processing chamber, and an operation in which the substrates are conveyed from the substrate mounting unit in the substrate processing chamber to the substrate storage unit. The substrate processing cycle in the substrate processing device can thereby be reduced, and the number of substrates processed per unit of time increased. The present invention allows any arrangement to be used for lining up the two substrate conveying units. The two units can be arranged side by side when device bulkiness is not a concern, or a more compact device can be devised by stacking the devices in a two-tier arrangement so that they substantially overlap when viewed from above. In comparison with the arrangement in which the two substrate conveying units are placed side by side, the two-tier arrangement requires a smaller substrate conveying chamber for accommodating the substrate conveying units, reduces the size of the entire device, and renders the device less expensive. In addition, the substrate conveying chamber can be evacuated faster, and a higher throughput can be obtained. It is also possible to conduct a rigid operation in which one of the two substrate conveying units is used exclusively for unprocessed substrates, and the other for processed substrates, although it is more preferable to abandon this rigid approach and to use the units interchangeably for alternately handling unprocessed substrates and processed, substrates.
The substrate processing device of claim 2 is obtained by modifying the substrate processing device set forth claim 1 such that at least two substrate storage units are provided, one of these substrate storage units is used to store unprocessed substrates, and the other substrate storage unit is used to store processed substrates. In the substrate processing device of claim 2, redundant operation of the substrate conveying device can be eliminated and the substrate conveyance time can be further reduced by bringing at least two substrate storage units in correspondence with two substrate conveying units.
The substrate processing device of claim 3 is obtained by modifying the substrate processing device set forth claim 2 such that a difference in height is established between the substrate mounting surface of the substrate mounting unit and the substrate mounting surface of the substrate storage unit for storing unprocessed substrates; and this difference in height is made substantially the same as the difference in height between the substrate mounting surface of the substrate conveying unit for conveying unprocessed substrates, and the substrate mounting surface of the substrate conveying unit for conveying processed substrates. Preferably, the substrate conveying device may be provided with a single lifting mechanism for simultaneously lowering or raising the substrate conveying unit for conveying unprocessed substrates, and the substrate conveying unit for conveying processed substrates, making it possible to receive the unprocessed substrates from the substrate mounting unit of the substrate processing chamber at the same time as the unprocessed substrates are received from the substrate storage unit for storing the unprocessed substrates of the substrate storage unit. When processed substrates are received in the substrate processing device of claim 3 from the substrate mounting unit of the substrate processing chamber at the same time as unprocessed substrates are received from the substrate storage unit for storing unprocessed substrates, providing the substrate conveying device with a single lifting mechanism allows the vertical operation thereof to be minimized, and the substrate conveyance time to be further reduced.
The substrate processing device of claim 4 is obtained by modifying the substrate processing device set forth in claim 2 or 3 such that the substrate storage unit for storing processed substrates and the substrate mounting unit are disposed so that a difference in height between the substrate mounting surface of the substrate mounting unit and the substrate mounting surface of the substrate storage unit produces; and this difference in height is made substantially the same as the difference in height between the substrate mounting surface of the substrate conveying unit for conveying unprocessed substrates and the substrate mounting surface of the substrate conveying unit for conveying processed substrates. Preferably, the substrate conveying device may be provided with a single lifting mechanism for simultaneously lowering or raising the substrate conveying unit for conveying unprocessed substrates, and the conveying unit for conveying processed substrates, making it possible to deliver unprocessed substrates to the substrate storage unit for storing the unprocessed substrates of the substrate storage unit at the same time as processed substrates are delivered to the substrate mounting unit of the substrate processing chamber. When processed substrates are delivered in the substrate processing device of claim 4 to the substrate storage unit for storing processed substrates at the same time as unprocessed substrates are delivered to the substrate mounting unit of the substrate processing chamber, providing the substrate conveying device with a single lifting mechanism allows the vertical operation thereof to be minimized, and the substrate conveyance time to be further reduced.
The substrate processing device of claim 5 is obtained by modifying the substrate processing device set forth in claim 1 such that a lifting mechanism is provided for raising and lowering the substrate storage units; the substrate storage units raised and lowered by the lifting mechanism are arranged in three or more tiers; the three or more substrate storage units operate during the raising or lowering of the substrate storage units by the lifting mechanism in such a way that one of these substrate storage units is brought to a height corresponding to the position occupied by the unprocessed substrate conveying unit of the substrate conveying device, establishing access from the unprocessed substrate conveying unit; and another substrate storage unit is brought to a height corresponding to the position occupied by the processed substrate conveying unit of the substrate conveying device, establishing access from the processed substrate conveying unit. The substrate processing device of claim 5 requires a shorter processing time interval because three or more tiers of substrate storage units are provided to perform parallel processing with the aid of these substrate storage units, and the three or more tiers of substrate storage units are raised or lowered by a lifting mechanism to establish access to any of these substrate storage units, and because the routine performed using these substrate storage units and considered to be the factor that determines the processing time interval of a device can be reduced if the time needed to process a substrate is shorter than the standard time needed to process a substrate.
The substrate processing device of claim 6 is obtained by modifying the substrate processing device set forth in claim 1,2,3 or 5 such that the substrate conveying units in the substrate conveying device are rectilinearly actuated, and the substrate conveying unit for conveying unprocessed substrates and the substrate conveying unit for conveying processed substrates are expanded or contracted in the opposite directions from each other. The two substrate conveying units provided to the substrate conveying device should preferably be allowed to expand and contract when rectilinearly actuated, and both the substrate conveying unit for conveying unprocessed substrates and the substrate conveying unit for conveying processed substrates should preferably be retracted into the substrate conveying device when in standby mode During substrate conveyance, one of the substrate conveying units (the one designed to convey conveying unprocessed substrates) extends from the substrate conveying device toward the substrate storage unit for storing unprocessed substrates to receive an unprocessed substrate, contracts temporarily, and extends through the substrate conveying device toward the substrate processing chamber to deliver the unprocessed substrate. The device should be configured such that the other substrate conveying unit (the one designed to convey processed substrates) extends from the substrate conveying device toward the substrate processing chamber to receive a processed substrate, contracts temporarily, and extends through the substrate conveying device toward the substrate storage unit for storing processed substrates to deliver the processed substrate. The substrate processing device of claim 6 makes it possible to reduce the area occupied by the substrate conveying device in proportion to the amount previously set aside for substrate rotation, and to efficiently use clean rooms containing such substrate processing devices.
The substrate processing device of claim 7 is obtained by modifying the substrate processing device set forth in claim 1 or 2 such that the substrate storage units are provided with a heater for heating unprocessed substrates, and a heating gas is heated by the heater and fed in a shower. According to the substrate processing device of claim 7, the substrate storage units are provided with a heater, and the substrates are preheated in the substrate storage units, making it possible to reduce the time needed to convey and process the substrates in the substrate processing device. The cost of equipment and the area (footprint) occupied by the equipment can also be reduced. In addition, the substrates can be uniformly heated because the heating gas heated by the heater is fed in a shower. In particular, using a resistance heater makes it possible to heat the substrates rapidly and accurately at low temperatures (200 to 300xc2x0 C.).
The substrate processing device of claim 8 comprises a single airtightly configured substrate processing chamber for processing substrates, a single substrate conveying chamber, and a single preparation chamber, provided in a sequential manner; a first valve that is provided between the substrate processing chamber and the substrate conveying chamber and that is designed to maintain an airtight condition between the substrate processing chamber and the substrate conveying chamber when closed and to allow the substrates to pass therethrough when open; a second valve that is provided between the substrate conveying chamber and the preparation chamber and that is designed to maintain an airtight condition between the substrate conveying chamber and the preparation chamber when closed and to allow the substrates to pass therethrough when open; a third valve that is provided between the preparation chamber and the atmosphere and that is designed to keep the preparation chamber airtight when closed and to allow the substrates to pass therethrough when open; and a cassette that is disposed at atmospheric pressure outside the preparation chamber and can stack plural substrates at substantially the same height as the preparation chamber and hold them; wherein the substrate conveying chamber is provided with a first substrate conveying device for allowing substrates to be delivered between the single preparation chamber and the single substrate processing chamber; and a second substrate conveying device for allowing substrates to be delivered is provided between the cassette and the preparation chamber.
There are known substrate processing devices in which a plurality of modules, each comprising a substrate processing chamber, a substrate conveying chamber, a preparation chamber, and one to three valves, are stacked up in the vertical direction with respect to a cassette loading chamber, and a substrate conveying device is provided to allow substrates to be conveyed to the preparation chamber of each of the linked modules as well as to a cassette whose position differs from the height of these preparation chambers. By contrast, the invention of claim 8 entails providing a single linked module comprising a substrate processing chamber, a substrate conveying chamber, a preparation chamber, and one to three valves, and disposing the cassette at substantially the same height as the preparation chamber. Consequently, the lifting mechanism for the second substrate conveying device kept at atmospheric pressure can be made lover than the mechanism of a conventional substrate processing device such as that described above, making it possible to reduce the costs incurred in manufacturing the device and to shorten the time needed to convey the substrates.
The substrate processing device of claim 9 is the substrate processing device, as defined in claim 8, wherein the substrate storage unit of the substrate preparation chamber is arranged within a range of the height of the mounting position of the plural substrates stacked in the cassette. Thereby the mechanism of the substrate conveying device is simplified more effectively, so that it is possible to reduce more the cost for manufacturing the device and to shorten more the time needed to convey the substrates.
The substrate processing device of claim 10 is the substrate processing device, as defined in claim 9, wherein the second substrate conveying device has a lifting mechanism, which raises and lowers within a range of allowing the substrate to be introduced and/or carried out, within the range of height of the mounting position of the plural substrates stacked in the cassette. Thus when the lifting mechanism is used as the mechanism provided in the second substrate conveying device, the lifting mechanism can be made lower more effectively, so that it is possible to reduce more the cost incurred in manufacturing the device and to shorten more the time needed to convey the substrates.
The substrate conveying device of claim 11 is a substrate conveying device for conveying unprocessed substrates from a substrate storage unit to a substrate mounting unit inside a substrate processing chamber, and conveying processed substrates from the substrate mounting unit inside the substrate processing chamber to a substrate storage unit, wherein this substrate conveying device is provided with two simultaneously operating substrate conveying units; one of these substrate conveying units is used to convey the unprocessed substrates from the substrate storage unit to the substrate mounting unit inside the substrate processing chamber; and the other substrate conveying unit is used to convey the processed substrates from the substrate mounting unit inside the substrate processing chamber to the substrate storage unit. In the substrate processing device of claim 11, the substrate conveyance time can be reduced by about half by providing the substrate conveying device with two substrate conveying units and simultaneously performing an operation in which substrates are conveyed from the substrate storage unit to the substrate mounting unit in the substrate processing chamber, and an operation in which the substrates are conveyed from the substrate mounting unit in the substrate processing chamber to the substrate storage unit. In particular, the two substrate conveying units should preferably have a two-tier configuration in which the units overlap when viewed from above. Using a two-tier configuration reduces the number of substrate conveying chambers needed to accommodate substrate conveying units, and allows the cost of the device to be reduced. In addition, the substrate conveying chambers can be evacuated faster, and a higher throughput can be obtained.
The substrate processing method of the claim 12 is a substrate processing method for performing an operation in which an unprocessed substrate is received by a second substrate support unit while performing an operation in which a processed substrate is received in a substrate processing chamber by a first substrate support unit; performing an operation in which the unprocessed substrate is introduced into the processing chamber by the second substrate support unit and the unprocessed substrate is subjected to prescribed processing in the substrate processing chamber after the processed substrate is received by the first substrate support unit and the unprocessed substrate is received by the second substrate support unit. The unprocessed substrate thus received is conveyed to a preparation chamber, but the processed substrate thus received may also be conveyed to a substrate storage unit or sent to the processing chamber of the next processing step. Consequently, the time needed to convey substrates can be reduced, the substrate processing cycle in the substrate processing device shortened, and the number of substrates processed per unit of time increased.
The substrate processing method of claim 13 is a substrate processing method, as defined in claim 12, for storing the processed substrate received by the first substrate unit while introducing the unprocessed substrate into the substrate processing chamber by the second substrate support unit. The time needed to convey the substrate can be further reduced by introducing the above-described received unprocessed substrate into the processing chamber while the operation to store the received processed substrate is being performed.
The substrate processing method of claim 14 is a substrate processing method, as defined in claim 12, for starting the operation for receiving the processed substrate and the operation for receiving the unprocessed substrate substantially concurrently. The substrate conveyance time can be minimized, the substrate processing cycle in the substrate processing device can be further reduced, and the number of substrates processed per unit of time can be further increased by starting the operation for receiving the unprocessed substrate substantially concurrently with the operation for receiving the processed substrate.